Absolute best dent filler????

[Stud37]

To long time car restoration project people. I would like to know what is the top of the line body filler. And not Bondo, as I read it isn’t a product that lasts 20 years because of deteriorating. The car I’m restoring is what I call a many generations car, so want it done right the first time. My car firewall number is 37CQ-2
email: oilandgastioga@gmail.com 

[mechanician]

Lead 70/30 Pb/Sn

[JustDave]

I owned a body shop two shops actually for over 35 years,I’ve seen bonds go bad in the first year,and I’ve seen it last over twenty,I’ve seen lead work go to hell after the first year,and I’ve seen it last many many years,I believe it’s all in the preparations,I had a metal man from Mexico work for me for over 20 years whenever he did lead when finished he would always wipe it down with vinegar,never ever seen any of his work go bad,but he was also the guy that came to work in a white work shirt and 90 % of the time it was white when he went home

[joe_padavano]

The "best" filler is none at all. Metal finish until no filler is needed. If the thickness is minimal, then pretty much any filler will work fine.

[Twisted Shifter]

[31Buick96S]

3 hours ago, joe_padavano said:

The "best" filler is none at all. Metal finish until no filler is needed. If the thickness is minimal, then pretty much any filler will work fine.

Properly finished metal work should be the first priority.  Lead work is a dying art, it is a difficult process to master and there aren’t that many people around who can do it or teach you how to do it. I’ve had good luck by spending extra time getting the metal work right and using a very thin coat of filler. I prefer the Evercoat brand. Follow the manufacturer instructions to the letter and use quality primer and paint. PPG is my brand of choice. 

[Akstraw]

I have had much success with Evercoat products as well.

[TAKerry]

I agree that the metal should be straight first. Lead may be the best if done properly, I dont know? There used to be a lot of old school stuff in the building industry that was the 'best' that pales in comparison to new products being developed. For body work I use Rage Gold. Its pretty good stuff. There is a huge difference between that and the bondo branded crap. I would think for an average restoration the use of these kind of products is not uncommon at all. I have seen pro shops that once the body is done they will skim coat the entire car and sand everything flat. That to me seems like excessive overkill and although the fill and sand is a bit of an art itself it seems to me to be covering a shortcoming in the initial body work phase. I have read arguments on both side of the fence regarding that process.

[R Walling]

 I have noticed that filler will not stick to very smooth metal. 

 

I have found that if you sandblast the area to be filled, it gives a clean and abraded surface that the filler will stick to.

 

 

 ( HOW MANY REMEMBER WHEN YOU HAD TO USE A GRINDER WITH A 36 GRIT IN ORDER TO SMOOTH THE FILLER?)😡

 

 

Edited February 20 by R Walling (see edit history)

[TAKerry]

I may be doing it wrong, but I put epoxy on the bare metal before doing any body work. Has worked out well for me. Cars are still holding up fine. I guess time will tell.

[TTR]

17 hours ago, joe_padavano said:

The "best" filler is none at all. Metal finish until no filler is needed. If the thickness is minimal, then pretty much any filler will work fine.

Exactly.

Generally speaking, any area, however small square inch/foot wise, requiring more than 1/8” thickness of any type of body filler, is usually far from adequately metal finished, but if a person is not able to achieve ready-to-spray metal finish, less than 1/16” thickness would be acceptable.

 

Excessive, i.e. 1/8“ thickness or more, use of any body fillers is usually a sign of an inexperienced amateur or cheap/quick collision repair center approach, not that there’s anything wrong with either, but shouldn’t be expected to last beyond few years, let alone a decade or two.

Edited February 20 by TTR (see edit history)

[joe_padavano]

1 hour ago, TAKerry said:

I may be doing it wrong, but I put epoxy on the bare metal before doing any body work. Has worked out well for me. Cars are still holding up fine. I guess time will tell.

Modern fillers adhere to epoxy primers. Priming first also keeps the surface clean.

[GrumpyJim]

Body filler generally doesn't go bad. It usually fails because of application techniques. Metal finish the repair are as best as possible. That is so it minimizes the amount of filler needed. Filler should never be more than 1/8th inch thick. Certainly no more than a 1/4 inch in extreme cases.

[Frank DuVal]

On 2/19/2024 at 4:05 PM, mechanician said:

Lead 70/30 Pb/Sn

While your 70% lead and 30% tin is correct,

 

Solder is commonly listed as Tin/Lead, so 30/70 is body solder.

 

60/40 is electronics solder, that's why I knew it was backwards. 😁

[Frank DuVal]

On 2/19/2024 at 5:18 PM, joe_padavano said:

The "best" filler is none at all. Metal finish until no filler is needed. If the thickness is minimal, then pretty much any filler will work fine.

Yep, that is correct, then reality sets in, and a filler of some sorts is required. Go ahead and put on a door skin and use no filler. 🤣

 

Even GM used lead to fix seams for years, and to fix cars damaged on the assembly line.

[Frank DuVal]

On 2/20/2024 at 8:25 AM, R Walling said:

( HOW MANY REMEMBER WHEN YOU HAD TO USE A GRINDER WITH A 36 GRIT IN ORDER TO SMOOTH THE FILLER?)😡

"Cheesegrater" file (Shurform) and then an 8" DA with 40 was my go to. 36 seems waaay to coarse, leaves too many deep sand scratches. OK, so does 40! But if you use 100 to rough out plastic filler then you will never get the area flat, just ripples.

 

In case it was missed, there was a change in body filler about 40 years ago. It went from dense (what the 36 comment was referring to) to "liteweight". The dense stuff could be used to fix gasoline tanks! Directions right on the can of Slix (Slicks?). Liteweight much easier to sand.

[R Walling]

19 minutes ago, Frank DuVal said:

"Cheesegrater" file (Shurform) and then an 8" DA with 40 was my go to. 36 seems waaay to coarse, leaves too many deep sand scratches. OK, so does 40! But if you use 100 to rough out plastic filler then you will never get the area flat, just ripples.

 

In case it was missed, there was a change in body filler about 40 years ago. It went from dense (what the 36 comment was referring to) to "liteweight". The dense stuff could be used to fix gasoline tanks! Directions right on the can of Slix (Slicks?). Liteweight much easier to sand.

 Now you are making me feel old with the 40 years ago comment!  (It was actually 50 years)🙄